Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
Condensed Consolidated Balance Sheets
Receivables, allowance for doubtful accounts	$ 80,195	$ 51,470
Preferred stock, par	$ 1	$ 1
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, issued	0	0
Common stock, par	$ 0.17	$ 0.17
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	192,739,787	190,244,741
Treasury stock, shares	25,910,263	21,795,051